Good morning everyone

Hoping someone can assist me with my first solar setup.

I am constantly getting OVP errors on my two Ecco batteries and I am not sure what is causing it. The setup is as follows:

1. Inverter Ecco 11KW.

   1. Running in SBU (Solar, Battery, Utility) output priority.

   2. Running SoF (Solar First) charger source priority.

   3. Battery type set to Li2 (Pylon US2000 protocol).

2. 2x Batteries (WS51100) in parallel (common busbar).

   1. Inverter RS485 to master battery RS485 port.

   2. Master Battery RS485A to Slave Battery RS485A.

   3. Dip on master (1,0,0,0), slave (0,0,0,0).

Ive tried running running Li4 at first, but no matter how I configured Dip settings or connected the batteries to each other (RS485A/B to each other) the BMS refused to connect resulting in the inverter throwing warning 4B (Lithium battery communication is abnormal). The only success I had in getting BMS setup was with Li2.

I am fairly certain the Li2 Pylon battery setting perhaps has charging limit voltage set too high. Although I thought the BMS would communicate these parameters.

Does anyone have experience setting up BMS between Ecco Inverters and Batteries, or perhaps know why these OVP errors are occurring?

Edit (forgot to include that I managed to catch the error as it happened):

Master battery:

1. Status: OVP

2. Pack Voltage: 54.54 V

3. Im: 0.00 A

4. SOC: 99.90 %

5. FCC: 101.0 AH

6. RM: 100.9 AH

7. CC: 5

Slave battery:

1. Status: OVP

2. Pack Voltage: 54.53 V

3. Im: 0.00 A

4. SOC: 99.99 %

5. FCC: 100.9 AH

6. RM: 100.9 AH

7. CC: 5

Ps. There isnt a massive number of these errors occurring the whole time, its maybe 1 a day.

Thanks

Edited March 19, 20251 yr by IronManZA
Included some additional information when I caught the batteries in OVP state.

2 hours ago, IronManZA said:

Edit (forgot to include that I managed to catch the error as it happened):

I am assuming its two of these? Yes?/No?

Either way, looking at the specs, 54,5V is not over voltage territory, so most likely is a cell going over the BMS' voltage limit, presumably 3.600V and this is giving you the error, this is usually tied to the BMS not being able to balance the cells with enough current to keep things in check. Since this is happening when the batteries are for all intents and purposes full, I'd consider 99.9% and 99.99% full, maybe talk to the supplier and see whether there is a firmware upgrade that addresses this issue or a known problem where some of the connections between the cell are dubious and need re-tightening, maybe...

Briefly back to 54.5V if calc (command line) isn't messing up, that would be 3.40625V per cell for a 16S battery, which these seem to be, so far from over voltage, unless the cells are really badly balanced...

59 minutes ago, Kalahari Meerkat said:

I am assuming its two of these? Yes?/No?

Either way, looking at the specs, 54,5V is not over voltage territory, so most likely is a cell going over the BMS' voltage limit, presumably 3.600V and this is giving you the error, this is usually tied to the BMS not being able to balance the cells with enough current to keep things in check. Since this is happening when the batteries are for all intents and purposes full, I'd consider 99.9% and 99.99% full, maybe talk to the supplier and see whether there is a firmware upgrade that addresses this issue or a known problem where some of the connections between the cell are dubious and need re-tightening, maybe...

Briefly back to 54.5V if calc (command line) isn't messing up, that would be 3.40625V per cell for a 16S battery, which these seem to be, so far from over voltage, unless the cells are really badly balanced...

Thanks for your reply.
Thats the exact battery yes :)
It does have 16 cells. I didn't have an in depth look at individual cell voltages and how balanced / unbalanced they are, but will pay attention if it hits OVP again.

@IronManZA ,

Agree with @Kalahari Meerkat , you need to monitor the cell voltages over time, specially under load (charge & discharge), as well as when close to 100%SOC. Hopefully you've discovered what BMS is inside the Battery, and it has a RS232 port, so you can use something like PBMSTools (for Pace BMS, for e.g.), that matches your BMS. Would be interesting to know what BMS/tool is required to monitor your battery via RS232.

BMS's normally have 2 OVP parameters.

1 for cell voltage typical 3.40V - you maybe need to set it up a little higher so the cell OVP doesn't trigger

2 for battery voltage typical 54.40V - you maybe need to set it up a little higher so the battery OVP doesn't trigger

BMS don't report/communicate this to the inverter, but merely reacts to it or not via Warnings/Alarms

Howdy,

This is "sort" of normal, depending on how good the BMS has been factory configured.

Eg. I struggled and was alarmed when I first connected my Battery ( Pace BMS ) as it instantly hit OVP on one cell after it's first charge.

My cells seemed out of balance as the one cell always shot up and the other cells were no where near 3.45v.

Over time the cells are slowly "normalising" and after ~ 28 cycles I now have 8 cells getting close to 3.45v , so they are balancing out.

Scouring a lot of forums, this seems to be normal behaviour, depending again on how much effort the factory put in to dialing in their settings.

It could take close to a 100 cycles for it all to balance out.

Some batteries are dialed in from the get go, others take longer.

Bottom line is , this behaviour is not unheard of, and kind of "normal"

2 hours ago, MrBeauvedere said:

Howdy,

This is "sort" of normal, depending on how good the BMS has been factory configured.

Eg. I struggled and was alarmed when I first connected my Battery ( Pace BMS ) as it instantly hit OVP on one cell after it's first charge.

My cells seemed out of balance as the one cell always shot up and the other cells were no where near 3.45v.

Over time the cells are slowly "normalising" and after ~ 28 cycles I now have 8 cells getting close to 3.45v , so they are balancing out.

Scouring a lot of forums, this seems to be normal behaviour, depending again on how much effort the factory put in to dialing in their settings.

It could take close to a 100 cycles for it all to balance out.

Some batteries are dialed in from the get go, others take longer.

Bottom line is , this behaviour is not unheard of, and kind of "normal"

I always wonder about this, I see my friends revov has like 60OVPS. But it seems svolt only allows certain amount of ovps under warranty.

Wonder how many ovps are okay.

27 minutes ago, Stefan Cornelissen said:

I always wonder about this, I see my friends revov has like 60OVPS. But it seems svolt only allows certain amount of ovps under warranty.

Wonder how many ovps are okay.

Without sounding like a negative Nelly and not to hijack OP's post too much, I will say this.

When I first experienced the OVP and started thoroughly researching this, I was confused as to why the manufacturer chose to implement the BMS config the way it did ( Balance threshold parameter set too high , so the cells start balancing too late and you sit with a "runaway cell" triggering a OVP and there is not enough time for cells to catch up and balance with grace :) )

As mentioned, over time the cells sort themselves out and balance at the expense of OVP's in the logs.

And the only logical conclusion I drew quickly was that this could be used as a potential argument to not having to honour warranty claims, even though by the implementation this is almost guaranteed to happen. So perhaps a case for voiding warranty claims is a side effect in favour of manufacturers due to a specific default setup by the BMS manufacturer.

Currently I am at 10 OVP's and only 50% there to a fully balanced battery.

It could also just be a Pace BMS thing and whatever battery manufacturer that uses that BMS doesn't bother to change it from the Pace factory default for the applicable hardware config (15s/16s).

On 2025/03/19 at 9:33 PM, MrBeauvedere said:

It could also just be a Pace BMS thing and whatever battery manufacturer that uses that BMS doesn't bother to change it from the Pace factory default for the applicable hardware config (15s/16s).

should the real name be a "Puis" BMS and thus, as a pimple, require removing from the battery system and be replaced with something betterer??? :-)